In Outlook, you have the option of which calendars to display in the Calendars folder. As shown in Figure 2, there is a checkbox beside each calendar in the My Calendars group. Figure 3 shows three calendars being viewed side-by-side. Outlook uses colors to help differentiate the calendars viewed in 'Side-by-Side' mode. Outlook also allows you to view calendar items all in the same calendar. This is called 'Overlay' mode and is shown in Figure 4. There are tabs at the top showing which calendars are participating in the view. Changing to another tab changes the focus to that calendar with the other calendar appointments faded slightly.
When working with Microsoft Exchange especially, you have the ability to open other users' folders where permission has been granted to do so. This is a common scenario for use of multiple calendars in this view by opening calendars of your staff, supervisor or peers. Calendars in Outlook can also be divided into groups. Figure 3 also shows the default groups of My Calendars and Other Calendars. An additional group labeled 'Development Team' has been added with other calendars therein.
Viewing multiple calendars in Outlook 2007 is both simple and valuable. It helps show conflicts or just easily compare schedules.